The tomato epidemic is not the first the country has seen, but it is the largest since an outbreak in 2004 sickened 564 people, said William Marler, a Seattle attorney who specializes in food contamination cases.

Marler has been involved in seven of the last 12 salmonella cases involving tomatoes in the last decade. This is the only one that has involved the salmonella Saintpaul strain, he said.

Overall, salmonella outbreaks linked to raw tomatoes are common. The CDC estimates salmonella poisoning from raw tomatoes has sickened as many as 79,000 people in 12 multi-state outbreaks since 1990.

Tomatoes usually are contaminated when salmonella bacteria enter the raw fruit through a puncture in its waxy skin, said David Acheson, the FDA’s associate commissioner for foods.